Apparatus for displaying the level of danger of the instantaneous driving situation of a motor vehicle

Abstract

A display arrangement for depicting the level of danger associated with current driving conditions of a motor vehicle. A control unit processes the vehicle's speed and its distance from the vehicle in front and presents a green circular area if the speed and the distance from the vehicle in front are in the permitted, instantaneously safe range. If the vehicle speed exceeds the permitted speed by a first limit amount, or if the distance from the vehicle in front becomes smaller than the distance which the vehicle covers within a first prescribed time period, the display changes gradually from the circular shape, to an elongated area with a shape which extends more horizontally than vertically, and the color of the area shown changes from green to yellow. If the permitted speed is exceeded by a second limit amount, or the distance from the vehicle in front becomes smaller than the distance which the vehicle covers within a second prescribed time period (for example, one second), the display changes to a symbol containing cognitively striking warning information and at the same time the color of the symbol shown changes from yellow to red.

What is claimed is: 
     
       1. Display arrangement for indicating to an operator of a motor vehicle an instantaneous degree of danger of driving conditions, said motor vehicle having sensors for detecting speed of said vehicle and distance of said vehicle from a vehicle in front, said display arrangement comprising: a visual display comprising a substantially planar screen for displaying two dimensional figures having continuously variable shape and color, said visual display screen being positioned in the vehicle and visible to said operator; and   a control unit coupled to receive output signals from said speed and distance sensors and having logic circuitry for causing said visual display screen to display a two dimensional figure having predetermined arbitrary shape and color, and for continuously varying said shape and color to indicate vehicle driving conditions according to the following   when said vehicle speed and said distance of said vehicle from a vehicle in front fall within respective first speed and distance limits which correspond to safe driving conditions, a circular figure having a first color is displayed as said two dimensional signal;   when said vehicle speed exceeds said first speed limit but is less than a second speed limit, or when said distance between said vehicle and said vehicle in front is less than said first distance limit but greater than a second distance limit, said display gradually changes said figure to an elongated shape having a major axis which is aligned with a first direction, and said shape changes from said first color to a second color; and   if said vehicle speed exceeds said second speed limit or said distance to said vehicle in front is less than said second distance limit, said display changes said visual signal to a third color, having a predetermined shape geometrically different from said elongated shape, and easily distinguishable therefrom.   
     
     
       2. Display arrangement according to claim 1 wherein when said display changes to an elongated area having a major axis aligned in the first direction, the color of said elongated shape changes, and eccentricity of said elongated shape increases, as said vehicle speed increases or said distance to said vehicle in front decreases. 
     
     
       3. Display arrangement according to claim 1 wherein said elongated area is substantially elliptical. 
     
     
       4. Display arrangement according to claim 2 wherein said elongated area is substantially elliptical. 
     
     
       5. Display arrangement according to claim 1 wherein said eccentricity of said elongated shape increases steadily with increasing vehicle speed and with decreasing distance from said vehicle to said vehicle in front. 
     
     
       6. Display arrangement according to claim 1 wherein said eccentricity of said elongated shape increases nonlinearly with increasing vehicle speed and with decreasing distance from said vehicle to said vehicle in front. 
     
     
       7. Display arrangement according to claim 1 wherein said easily identifiable shape is an elongated area having a maximum eccentricity. 
     
     
       8. Display arrangement according to claim 7 wherein said elongated shape is an ellipse. 
     
     
       9. Display arrangement according to claim 1 wherein said easily identifiable shape is substantially triangular. 
     
     
       10. Display arrangement according to claim 1 wherein said easily identifiable shape is substantially rectangular. 
     
     
       11. Display arrangement according to claim 10 wherein said rectangular shape substantially completely fills a display screen of said visual display. 
     
     
       12. Display arrangement according to claim 1 wherein said control unit further causes said visual display to change said two dimensional visual signal according to the following: when said vehicle speed and said distance of said vehicle from the vehicle in front is less than said first speed and distance limits by a predetermined margin of safety, said display changes said shape to an elongated area having a major axis aligned in a second direction perpendicular to said first direction.   
     
     
       13. Display arrangement according to claim 12 wherein when said display changes to an elongated area having a major axis aligned in said second direction, eccentricity of said elongated shape increases as said vehicle speed decreases or said distance to the vehicle in front increases. 
     
     
       14. Display arrangement according to claim 13 wherein said elongated shape is an ellipse. 
     
     
       15. Display arrangement according to claim 1 wherein said first direction is horizontal. 
     
     
       16. Display arrangement according to claim 12 wherein said first direction is horizontal and said second direction is vertical. 
     
     
       17. Display arrangement according to claim 1 wherein at least a numerical display of current vehicle speed is superimposed on said two dimensional visual signal. 
     
     
       18. Display arrangement according to claim 12 wherein at least a numerical display of current vehicle speed is superimposed on said two dimensional visual signal. 
     
     
       19. Display arrangement according to claim 1 wherein said vehicle display displays further information concerning operation of said vehicle in addition to said two dimensional visual signal. 
     
     
       20. Display arrangement according to claim 12 wherein said vehicle display displays further information concerning operation of said vehicle in addition to said two dimensional visual signal. 
     
     
       21. Display arrangement according to claim 19 wherein said further information concerns fixed objects detected in bends in a roadway. 
     
     
       22. Display arrangement according to claim 1 wherein said visual display presents at least one additional signal from one of an infrared visual range measuring system and a system for measuring a coefficient of friction between a tire of said vehicle and a road on which it is operated. 
     
     
       23. Display arrangement according to claim 1 wherein brightness of said visual display is responsive ambient brightness of a passenger compartment of said vehicle. 
     
     
       24. Display arrangement according to claim 1 further comprising: means for receiving information from an external information source concerning speed limits applicable to a road on which said vehicle is operated; and   means for processing said information;   said control unit being responsive to said processed information for generating said two dimensional signals.